Boad-working machine



D. B. McCALL.

ROAD WORKING MACHINE. APPLICATION FILED AUG. 7, 1920.

1,410,585, Patented Mar. 28,1922.

5 SHEETS-SHEET l.

D. B. McCALL.

ROAD WORKING MACHINE.

APPLICATION FILED AUG. 7. 1920.

1,410,585, Patented Mar. 28, 1922 5 SHEETS-SHEET 2- D. B. McCALL.

ROAD WORKING MACHINE.

APPLICATION FILED AUGJ, 1920.

1,410,585. I Patented. Mar. 28, 1922.

5 SHEETSSHEET 3- Q a, /7/// lil D. B. McCALL.

ROAD WORKING MACHINE.

APPLICATION FILED AUG. 7. 1920.

1,410,585, Patented Mar. 28, 1922.

5 SHEETS.SHEET 4.

0. B. McCALL.

ROAD WORKING MACHINE- APPLICATION FILED AUG- 7; 1920- lfilfififi,Patented Mar. 28, 1922.

5 SHEETS-SHEET 5.'

7 surface of the roadway.

t me at Ta azz army lBe. it :lmown that- MCCALL, a citizen ofqthelUnitedQ'States re siding at oscow, in the county of Folk and Stateof Taxas, have invented certain new and useful Improvements in Road-'Working Machines, of which the following is a specification, referencebeing had to the accompanying drawings.

This invention relates to certain improve-- ments in road workingmachines, and it is an object of the invention to provide a device ofthis general character having novel and improved means whereby the samemay efiectively scrape and'substantially level the Another object of theinvention is to provide a novel and improved device of this generalcharacter embodying a spiral work,

ing member supported in a manner whereby the'same may be bodily shiftedin a. direction transverse to the direction of travel of the machine andin accordance with the reprovide a novel and improved device of thisgeneral character comprising a spirally arranged working member,togetherwith means adapted for coaction with said working member for cleaningthe same when re quired,

The invention consists in the details of construction and, in thecombination andarrangement of the several parts of my improved roadworking machine whereby certain important advantages are attained andthe device rendered simpler, less expensive and otherwise moreconvenient and advantageous for use, as will be hereinafter more fullyset forth.

The novel features of my invention will hereinafter be definitelyclaimed.

In order that my invention may be the mea e agent 19M;- are i no. comer,

Patented Mar, 28 192% better understood, I will now proceed to descrlbethe same with reference to the ac= companying drawings, wherein r Figure1 me view in top dplan ofa roadworking machine constructe in accordancewith an embodiment ofmy invention with a portion thereof diametricallydisclosed.

Figure 2 is a view in side elevation of the structure as illustrated inFigure l.

F gure 3 is an enlarged. fragmentary view 1n top plan illustrating indetail the yieldable or compensating member comprised in the element forholding the ground working member against movement in a directiontransverse to the direction of travel of the machine independently ofthe supporting structure for said working member.

Figure 4 is an enlarged fragmentary view 1n top plan illustrating indetail the yieldable connection between the alined sections comprised inthe driven shaft carried by the supporting structure for the workingmember.

Figure 5 is an enlarged fragmentary view partly in section and partly inelevation illustrating in detail certain parts of the mechanism foroperating the rotating working member and for mounting the forwardportion of the supporting structure for said member.

Figure 6 is a fragmentary view partly in top plan and partly in sectiontaken through the structure illustrated in Figure 5.

Figure 7 is a fragmentary view in side elevation of an end portion ofthe rotary working member and the supporting structure coactingtherewith.

Figure 8 is a fragmentary view partly in elevation and partly inlongitudinal section of .the structure illustrated in Figure 7.

Figure 9 is an" enlarged fragmentary view in top plan with a portion insection illustrating in detail the means whereby movement may beimparted in either direction to the supporting structure for the rotaryworking member.

Figure 10 is a view partly in elevation and partly in sectionillustrating in detail the mounting of the supporting structure for therotary working member.

Figure 11 is an enlarged fragmentary view partly in elevation and partlyin sec- L va;

-tion illustrating additional. details of the.

means for imparting movement to the sup porting structure for the rotaryworking member.

Figure 12 is an enlarged fragmentary view partly in section and partlyin elevation illustrating the means herein embodied ber beingfragmentarily shown in elevation,

and

Figure 15 is a fragmentary'view partly in top plan and partly in sectionillustrating a means for maintaining the structure illustrated in Figure12 in neutral.

As disclosed in the accompanying drawings, T denotes a tractor,preferably of a caterpillar type, and which includes a frame extendingforwardly of the traction mechanism and which frame embodies a supple--mental frame 1 extending to one side of the main frame and atsubstantially right angles thereto. The end members or beams 2 of thesupplemental frame are connected adjacent their inner ends by the beamor track 3 in parallelismwith the outer side beam or track 4 of the.supplemental frame and which beams 3 and 4 comprise a trackway alongwhich is adapted to travel a supporting structure S. Each of the beamsor tracks 3 and 4 in its upper and lower faces is provided'with thegrooves 5 for a purpose to be hereinafter more particularly referred to.

The supporting structure S comprises two beams 6 arranged in parallelismand extending transversely of the supplemental frame 1 and are tied orconnected adjacent their opposite end portions by the cross beams 7 and8. The forward end portions of the beams 6 are continued by the upwardlyinclined and converging extensions 9 of desired length and terminatingin the spaced straight portions 10 arranged in parallelism. Interposedbetween the opposite extremities of the portions 10 are the upstandingbearings 11 having their upper end portions connected by the'reinforcing or bracing member 12 so that the bearings 11 will bemaintained rigid or against displacement.

Rotatably supported between the portions 10 is a disc 14 carried by theupper end portion of a shank 15. The upper peripheral portion of thedisc '14 is provided with a' worm rack 16 with which is enga ed a worm17. The worm 17 is carried by t e shaft 18 wardly of the convergingextensions 9. The

shaft 18 is adapted to be rotated in any deinstrumentality of a crank 20carried by the inner end portion'of said shaft, whereby the shaft 18 maybe manually operated as required and in order to swing the shank 15 asthe requirements of practice may necessitate.

The lower portion of the shank 15 is provided with a socket 21 in whichis engaged the upstanding shank 22 comprised in the fork 23. The fork 23rotatably carries a supporting wheel 24 which is adapted to travel overthe roadway or other surface and whereby a support is provided for theforward end portion of the machine. By swinging the shank 1 5 in eitherdirection beyond the vertical or preferably rearwardly, the forwardportion of the machine, and more particularly the supporting structureS, may be lowered and vice versa.

The rear or inner bearing 11 is carried by a block 25, bolted, as at 26,or otherwise rigidly secured between the rear extremities of theportions 10. The block 25 and the bearing 11. carried thereby comprisetwo separable sections arranged side by side when in assembled relation,and depending from each section of the block 25 is a semispherical body27. When the sections of the blocks 25 and the members 27 are assembled,a socket 28 is provided, the members 27 being clamped, as at 29, orotherwise held in proper relation.

Extending within the socket 28 through the forward wall thereof is astub shaft 30 to the outer or exterior end portion of which is fixed agear 31. The opposite or inner portion of the wall of the socket 28 isprovided with a vertically disposed slot 32 arranged slightly to oneside of the stub shaft 30, although this is not imperative.

Extending through the slot 32 is a tubular member 33 and the insertedend portion of the member 33 is provided with a head 34 contacting withthe inner face or wall of the socket 28. The outer oropposite endportion of the tubular member 33 is provided with a substantiallyU-shaped head or casting 35, to the side arms 35 of which are securedthe forward end portions of the downwardly inclined and rearwardlydiverging beams 36.

The lower or rear portions of the beams 36 terminate in the dependingportions 37 provided with the feet 38 riveted, as at 39, or otherwisesecured to the opposite end portions of the blade 40. The blade 40 isarcuate in cross section and has its lower marginal portion formed intoa knife edge sired manner but preferably through the intone 43. Theforward end portion of each of.

the arms 42 is connected with the'adjacent beam 36 by a bracing orreinforcing member 44.

Fixed in each of the bearings 43 is anend portion of a stationary ornon-rotating shaft 45 arranged at substantially the axial center of theblade 40.. Rotatably mounted on the shaft 45 and snugly fitting betweenthe bearings 43 is a rotatable tubular shaft 46. The shaft 46 rotatesabout the stationary shaft 45 and, if desired, suitable anti-frictionmeans may be interposed between the shafts 45 and 46 so that the shaft45'may operate with a minimum of frictional resistance. This, however,is a well known mechanical expedient and a detailed illustration anddescription thereof is believed unnecessary.

Extending from substantially one end of the shaft 46 to the other is aspiral scraping blade B, said blade being continuous and encircling theshaft 46. The periphery of the blade B closely approaches the inner faceor wall of the blade 40 and as the shaft 46 is rotated, the blade B,when the beams 36 are in proper position, engage the roadway or othersurface and serves to efi'ectively scrape the same and at the same timecarrying the material loosened thereby to one side of the machine,whereby provision is made to fill any ruts or the like which may be.inthe surface being worked. This is facilitated in view of the fact thatthe blade 40 serves as a barrel to facilitate the travel of the loosenedmaterial lengthwise thereof. Said blade 40 also serves as an additionalmeans to scrape the roadway or other surface and to facilitate theleveling of said surface.

One end portion of the shaft 45 has fixed thereto a gear 47 meshing witha gear 48 carried by the lower end portion of a vertically disposedshaft 49. The shaft 49 is rotatably mounted in the bearings 50 carriedby the adjacent arm 42 and bearing 43 carried thereby. The upper endportion of the shaft 49 is provided with a gear 51 meshing with a gear52 carried by the outer end portion of a transversely disposed shaft 53.The outer end portion of the shaft 53 is rotatably supported by anupstanding bearing 54 carried by the adjacent portion of the arm 42while the inner'end portion of the shaft 53 is rotatably supported by abearing 55 depending from' the adjacent beam 36.

The inner end portion of the shaft 53 has fixed thereto a gear 56meshing with a car 57 fixed to the inner end ortion of a s aft 58. Theshaft 58 exten s forwardly and substantially in, arallelism with theadscent beam 36 an extends within the sec et 28 through the tubularmember 33. The end portion of the shaft 58 within the socket 28 isoperatively engaged with the stub shaft 30 through the instrumentalityof a universal joint 59, so that the shaft 58 may be driven through thestub shaft 30 to effect the requisite rotation of the tubular shaft 46and also to permit the desired vertical adjustment of the beams 36 andthe parts carried.

thereby without interfering with or hindering the desired rotation ofsaid tubular shaft 46.

The assembled sections 27 of the socket member also provide a dependingbearin 60 which rotatably supports the forward end portion of a driveshaft A in operative connection with the gear 31 through the gear 61fixed to the forward end portion of the shaft A. The shaft A extendsrearwardly and has its rear part rotatably supported b the side members7 and 8 of the structure L and fixed to the rear end portion of theshaft A is a gear 62 meshing with a car 63 carried by the transverselydispose shaft 64 rotatably supported by the supplemental frame 1. Thegear 63 is keyed to the shaft 64 for rotation therewith but in a mannerwhereby said gear 63 may move longitudinally or lengthwise of the shaft64 as will be hereinafter more particularly referred to and forvghichreason the side beam 8 of the structure S has fixed thereto abearing 65 through which the shaft 64 is freely disposed.- The gear 63is interposed between the bearing 65 and the gear 62 so that when thestructure S is moved in either direction longitudinally of the shaft 64,the gear 63 will be maintained in mesh with the gear 62.

The shaft 64 is operatively engaged at one end portion. as at 66. with ashaft 67 rotatably supported by the main frame of the tractor and hereindisclosed as extending longitudinally thereof. The shaft 67 is adaptedto be operatively engaged through the instrumentality of the chain 68 orotherwise as may be preferred with a motor M. The motor M may be of suchconstruction as to also operate to drive the tractor or, if preferred,the motor for rotating the shaft 67 may be independent of the motor forof the forward sections of the shaft A are loosely supported within anelongated sleeve 70 and said adjacent end portions of the forwardsections are connected by a spring 71 encircling the sleeve 70 andhaving its opposite end portion anchored as at 72 to the shaft sections.The tension of the spring 71 is sufficient to normally tie the forwardsections of the shaft A for unitary rotation but in the event any undueobstruction or hindrance may be offered to the spiral blade B, thespring 71 will permit slight relative rotation between the forwardsections of the shaft A. In the event that such obstructionshould ofierexcessive resistance, the spring 71 will break. This, however, is ofmaterial advantage as the spring 71 may be readily and convenientlyreplaced while provision is made to prevent any injury to the otherparts of the mechanism. It will be understood, however. under certainconditions when the operator observes that the blade B is not rotating,he can stop the r0- tation of the shaft 64 and take the necessary stepsto remove the interference or obstruc tion.

As is particularly illustrated in Figure 1, the shaft 46 and the blade40, which are substantially in parallelism, are arranged on an inclinewith respect to the longitudinal diameter or axis of the completemachine and which arrangement materially facilitates the functioning ofthe blades 40 and B.

During a working operation, it is of utmost importance that the blades40 and be bodily shifted transversely of the machine and particularly topermit the advance of the blades may be maintained in substan tially astraight line independently of the variations of travel which may oc urin the advance of the tractor. This bodily shifting of the blades 40 andB is also of material advantage in permitting said blades eitherlto workout from or into the ditch at one side of the roadway, the direction oftravel of the material being dependent upon the direction of travel ofthe tractor when the blades are in working engagement with the roadway.v

Each of the beams 6 has depending therefrom the bifurcated plates 73straddling the beams or trackways 3 and '4 from above. The arms 73 ofeach of the plates 73 above and below the coacting beam or track 3 or 4are connected by the shafts 74 carrying the wheels or rollers 75 ridingin the grooves 5 hereinbefore referred to whereby the supportingstructure S is permitted to have movement lengthwise of the beams ortracks 3 and 4 with a minimum of frictional resistance.

The end members or beams 2 of the supplemental frame 1 at a pointbetween the beams or tracks 3 and 4 are connected by the bar or beam 76provided in its upper surface with a worm rack 77 and the intermediateportion of the bar or beam 76 is further supported by a bracket 78depending from each of the beams 6. The bar or beam 76 is freelydisposed through each of the brackets 78 so that no obstruction isoffered thereby to the desired movement of the supporting structure Salong the beams or tracks 3 and 4.

The beams 7 and 8 of the supporting structure S to one side of the shaftA are connected by the spaced beams 79. The beams 79 are substantiallyin parallelism and coplanar with the inner section of the shaft A.Rotatably supported by the beams 79 above the bar or beam 76 is a worm80 in mesh with the worm rack 77, the opposite end portions of the wormbeing provided at the axial center thereof with the trunnions 81disposed through and rotatably engaged with the beams 79. 81 adjacentthe shaft A has fixed thereto a conical beveled frictionwheel 82positioned between the beveled friction wheels 83 carried by a sleeve orbarrel 84. The

sleeve or barrel 84 surrounds the adjacent portion or section of theshaft A and is provided in one end with an open slot 85 extendinglongitudinally thereof and through which is disposed a pin 86 carried bythe shaft A. By this means the sleeve or barrel 184 is mounted upon saidshaft for rotation therewith but capable of movement lengthwise of theshaft so that the sleeve 84 may be adjusted to position the wheels 83 inneutral or in a direction to cause either of the Wheels 83 tofrictionally engage the wheel 82 in accordance with the direction inwhich it is desired to rotate the worm 80 and depending upon thedirection in which it is desired to move the supporting structure S. Thesleeve 84 may be moved longitudinally of the shaft A in any mannerdesired but, as herein disclosed, one end portion of the sleeve 84 isprovided with the circumferentially disposed annular groove or channel87 with which coacts in a conventional manner the operating lever 88. Asis particularly illustrated in Figure 12, the lower end portion of thelever 88 is pivotally engaged with an arm or lug 89 positioned below theshaft A and suitably anchored to a bearing bracket 90 coacting .with theshaft A.

The lever 88, as particularly illustrated in Figure 15, is provided withan outstanding tooth 91 adapted to engage within a notch 92- carried bya rearwardly directed arcuate arm 93 also supported by the bracket 90but positioned above the shaft A. When the tooth 91 is seated within thenotch 92, the wheels 83 are ositively maintained in neutral yet butSlIght manual exertion is required to disengage the tooth 91 when it Thetrunnion is required to adjust the sleeve 84 to brin either of thewheels 83 into contact wit the wheel 82.

In practice, it is of utmost importance and advantage to provide meansfor maintaining clean the working edge of the blade B as otherwise therewould be a tendency of the spaces between the convolutions of saidblades becoming choked due to the material which would possibly adherethereto.

The arms 42 at a point in advance of the bearings 4:3 are connected by arod 94 preferably circular in cross section and which is non-rotatable.Surrounding the rod 94 but of a length less than the length of said rodis a sleeve'95 which is normally maintained 'at the limit of itsmovement in one direction, as occasioned by contact of the arm 42,through the medium of the expansible spring 96 interposed between thesecond arm 42 and the adjacentend of the sleeve 95. One end portion ofthe spring 96 is secured to the rod 94 while the opposite end portionthereof is secured to the adjacent end of the sleeve 95 so that thespring 96 also serves to constantly rotate .the sleeve 95 upwardly. Theinner end portion of the sleeve 95 is also provided with alongitudinally disposed extension 97 and which forms part of a head 98suitably secured to the end portion of the sleeve 95 extending entirelytherealong.-

Extending rearwardly from the head 98 and the portion thereofconstituting-the extension 97 are the cleaning fin ers 99, said fingersbeing spaced apart a istance substantially equal to the maximum spacebetween adjacent convolutions of the blade B and areof a number one lessthan the number of said convolutions of the blade.

The spring 96 operates to normally maintain the cleaning fingers 99 outof contact with the blade B but when it is desired to effect a cleaningoperation of said blade B,

4 the sleeve 95 is rocked in a direction to move said fingers 99downwardly into the requisite contact with the blade B. In the presentembodiment of my invention, this rocking movement of the sleeve 95 isaccomplished through the medium of a forwardly directed rock arm 100carried by the sleeve 95 and which has engaged with its outer or freeend portion a flexible member 101 extending upwardly over a suitableguide 102 comprised in the frame 19. By pulling upon the flexible member101, the operator may cause the fingers 99 to be brought into contactwith the blade B. With the fingers 99 in contact with the blade B and asthe shaft 46 rotates, the sleeve 95 will be caused to move along the rod99, placing the spring 97 under compression. The rod 94 is provided withan outstanding pin 103 extending through a slot 104 produced in the wallof the sleeve 95 and extending longitudinally thereof, the inner endportion of the slot vigil osition, the operator releases the flexiblemember 101,-whereupon-the spring 97 automatically returns or moves thesleeve 95 to ts normal position. When the sleeve 95 is in its normalposition, the sleeve 1'03; carried by the rod 94 is in contact with";the lower longitudlnaledge ofthe slot 10% which is of alength greaterthan the opposedilongitudlnal slot. The slot 104: is of suchwidth thatwhen the sleeve 95 is rocked downwardly to bring the fingers 99, intocontact with the blade B, the pin 103 will substantially contact wlththe upper or shorterlongitudinal edge of the slot 104: so that said pin103 will have the desired coaction with the inner cam edge 105.

It has also been found of particular advantage to provide means to bracethe beams 36 against the lateral strain which. it's-imposed thereon whenthe bladejB' is in workmg contact with the road surface or the like andas herein embodied such means comprises a flexible element E connectedat-one end to the rear end ortion of a beam ,36 and at its opposite endportion to thebeam 6 of the supporting structure remotefrom the a beam36 to which the element E is seciired. The element E, as herein setforth, comprises two sections having their adjacent The beams 36 areconnected by a trans-' versely directed member 107 and operativelyengaged with each end portion of the member 107 is the lower extremityof a vertically disposed rod 108. The upper end portion of each of therods 108 is operatively engaged with a crank 109 carried by ahorizontally disposed shaft 110 rotatably supported by the frame 19.Each of the shafts 110 has fixed thereto a worm wheel 111 meshing with aworm 112 carried by a transversely d posed sha t 113 re tatebly spported by the frame 19. The shaft 113 has' fixed thereto a hand wheel114. The cranks 109 are reve'rsely directed so that the blades B and 40may be virtually adjusted in accordance with the incline desired or canbe substantially horizontally disposed. This requisite verticaladjustment of the blades B and 40 is readily obtained by rotating thehand wheel 114 in the necessary or required direction.

From the foregoing description it is thought to be obvious that a roadworking machine constructed in accordance with my invention isparticularly well adapted for use by reason of the convenienceand-facility with which it may be assembled and operated, and it willalso be obvious that my invention is susceptible of some change andmodification without departing from the principles and spirit thereofand for this reason I do not wish to be understood as limiting myself tothe precise arrangement and formation of the several parts hereln shownin carrying out my invention in practice except as hereinafter claimed.

I claim:

1. A road working machine comprislng a portable body, a supportingstructure mounted thereon for movement in a direction transversely tothe direction of travel of the portable body, a scraping element carriedby the supporting structure, said supporting structure extending inadvance of the portable body, and supporting means for the forwardportion of said supporting structure riding over the surface'upon whichthe portable body traverses, said supporting means having swingingmovement about a substantially horizontally disposed axis to vary theposition of the scraping element relative to the surface over which themachine traverses.

2. A road working machine comprising a portable body, a supportingstructure mounted thereon for movement in a direction transversely tothe direction of travel to the surface over which the machine traverses.

3. A road working machine comprising a portable bod a spiral workingmember carried there y, means for bodily shifting the spiral workingmember in a direction transverse to the direction of the portable bodyand maintain the same angle of the workmg member with respect to thedirection of travel of the machine, means for :0

tating the spiral working member, and a scraplng blade positionedrearwardly of the spiral working member and movable therewith when thespiral working member 1s shifted transversely.

f4. A road working machine comprising a portable body, a spiral workingmember carried thereby, means for bodily shifting the spiral workingmember in a direction transverse to the direction of the portable bodyand maintain the same angle of the working member with respect to thedirection of travel of the machine, means for rotating the s iralworking member, and a scraping blad spiral Working member and movabletherewith when the spiral working member is shifted transversely, saidblade being arouate in cross section and operating as a barrel tofacilitate the functioning of the spiral working member.

5. A road working machine comprising a portable body, a supportingstructure mounted thereon and movable in a direction transverse to thedirection of travel of the portable body, means for shifting thesupporting structure in either direction, and scraping means carried bythe supporting structure, said scraping means at all times having thesaid angular relation to the direction of travel of the machine.

6. A road working machine comprising e positioned rearwardly of the aportable body, a rotary scraping element carried thereby, the axis ofsaid element be ing dlsposed in a direction transverse to the directionof travel of the portable body,

means for rotating said scraping element, and mechanism operated fromsaid last named means for bodily shifting the scraping element in adirection transverse to the direction of travel of the portable body andmaintain the same angle of the axis of the.

element with respect to the direction of travel of the machine.

7. A road working machine comprising a portable body, a supportingstructure mounted thereon, a pair of beams, a coupling connectingsimilar ends of the beams and the supporting structure and permittingthe beams to have vertical movement, a rotary scraping element sup ortedby the beams, a shaft supported y one of the beams and in drivingconnection with the rotary scraping element, a shaft carried by thesupporting structure and in drivin connection with the shaft carried bythe am, and means for rotating said second shaft.

8. A road working machine comprising a portable body, a supportingstructure mounted thereon, a pair of beams, a coupling connectingsimllar ends of the beams and the supporting structure and permit! tingthe beams to have vertical movement, a rotary scraping element supportedb the beams, a shaft supported by one o. the

beams and in driving connection With the rotary scraping element, ashaft carried by the supporting structure and in driving conncction withthe shaft carried by the beam, means for rotating said second shaft,said supporting structure being movable with respect to the portablebody, and coacting means carried by the supporting structure and thesecond named shaft operating at will to move said supporting structurein different directions.

9. A road working machine comprising a portable body, a supportingstructure mounted thereon, a pair of beams, a coupling connectingsimilar ends of the beams and the supporting structure and permittingthe beams to have vertical movement, a rotary scraping element supportedby the beams, a shaft supported by one of the beams and in drivingconnection With the rotary scraping element, a shaft carried by thesupporting structure and in driving conncction with the shaft carried bythe beam, means for rotating said second shaft, said second named shaftcomprising separable sections, and yieldable means for connecting saidsections and normally causing the same to have unitary rotation.

10. A road Working machine comprising a port-able body, a supportingstructure mounted thereon, a pair of beams, a coupling connectingsimilar ends of the beams and the supporting structure and permittingthe beams to have vertical movement, a rotary scraping element supportedby the beams, a shaft supported by one of the beams and in drivingconnection With the rotary scraping element, a shaft carried by thesupporting structure and in driving con nection with the shaft carriedby the beam, means for rotating said second shaft, and means connectingone of the beams and the supporting structure for holding the beams andthe rotary scraping element carried thereby against undue independentmove ment in a direction axially of the rotary scraping element.

In testimony whereof I hereunto affix my signature.

DANIEL B. MQCALL.

